Do you have a tracking number, or has it not been shipped yet?
By the way, make sure that you take advantage of their price match guarantee. Go to Newegg, TigerDirect, or one of the other sites they will match and let them know if you find a cheaper deal on the same hardware.
I have had very good results with Best Buy in the past. I was even able to return a video card directly to the store with no questions asked on an on-line purchase.